|  | 2.1 | Various LAN Communication Problems
| 2.1.3 | Half-duplex Ethernet
Ethernet is a half-duplex technology. Each Ethernet host checks the network to see whether data is being transmitted before it transmits additional data. If the network is already in use, the transmission is delayed. Despite transmission deferral, two or more Ethernet hosts can transmit at the same time, which results in a collision. When a collision occurs, the host that first detects the collision will send out a jam signal. Upon hearing the jam signal, each host will wait a random period of time before attempting to transmit. The NIC's backoff algorithm generates this random period of time. As more hosts are added to the network and begin transmitting, collisions are more likely to occur. Ethernet LANs become saturated because users run network-intensive software, such as client/server applications, which cause hosts to transmit more often and for longer periods of time. The physical connector (e.g. NIC) used by devices on an Ethernet LAN provides several circuits so that communications between devices can occur.
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